Th9 cells in immunity and immunopathological diseases

Excerpt

Nine is a magic number in mythology. Starting with the nine deities of Heliopolis in ancient Egypt, the strong association of the number nine with the Chinese dragon (a symbol of magic and power) to the nine muses in Greek mythology (including Kalliope, the muse of epic poetry and science), the number nine has always been associated with extraordinary skills. Thus, it comes as no surprise that T helper cells producing the cytokine interleukin-9 (IL-9) appear to mediate extraordinary functions. In this issue of Seminars in Immunopathology, we discuss the role of Th9 cells, the T helper subset producing IL-9, in immunity and immunopathological disorders. We have contributed and invited reviews from experts in the Th9 field to discuss the development and function of Th9 cells. The articles span topics ranging from the beginning of the field, to the signals and factors that promote development, to the beneficial and disease-related conditions where Th9 cells have been identified. Interestingly, current findings indicate that such Th9 cells are key players in immunology with a broad range of functions ranging from white to dark magic. Needless to say, in the latter context, the hell described in Dante’s Divine Comedy consisted of nine circles. Prepare to be enchanted by the heaven and hell that are Th9 cells. …